Today: Moving from the individual to the collective


Evolution of communities


Evolution of communities: Nothing exists in isolation



Show me one single, isolated tree in a Appalachian forest…





Biological implications of change


Philosophical implications of change

Global change pressures affect biological interactions


Cascading effects across many species




Every time community composition changes (by species gains, losses, or altered timing, strength, or type of interactions), shit happens


This is what we are doing on (and to) the planet


Individual species move, adjust, adapt, die and we care about that, but it’s the cascading effects that can unravel the biosphere as we know it

Cascading effects: co-extinction



Obvious examples like co-extinction where direct interaction partners influence each other














e.g., most vulnerable are obligate interaction partners (can be hosts/mutualists, predators/prey, plants/herbivores prey, hosts/parasites, etc.)

Cascading effects: keystone predator



  • But species impact each other even if they don’t interact directly through biotic interaction chains

Cascading effects: introduced species



And this doesn’t need to be a top-down keystone predator; it can be a bottom-up effect

Global worming


  • The last ice sheet killed off earthworms in the northern 1/3 of North American
    • worms—with their limited powers of dispersal—weren’t able to recolonize on their own


Humans move worms, via dirty ship ballast, horticultural plants, mulch and fishing bait. European earthworms live on every continent except Antarctica.


  • North American hardwood forests develop a thick blanket of slowly decomposing leaves deposited over the course of years that create homes for insects, amphibians, birds, and native flowers
    • worms breakdown this layer to quickly for plants to capture nutrients and insects lost their homes

Cascading effects: complex chains



  • Changes can have impacts many trophic levels away
    • trophic levels = feeding relationships

Cascading effects: complex webs


And these biotic interaction chains are actually embedded in complex biotic interaction webs

Cascading effects: the big picture


And these biotic interaction chains are actually embedded in biotic interaction webs plus complex abiotic interactions (Chap 10)

Evolution of communities


So we come back to… Nothing exists in isolation





Biological implications of change


Philosophical implications of change

True interconnectedness



Web of life is not some cheesy new-age idea


It’s also not just a scientific concept


It’s represented in cultures around the world


And it is quite simply: TRUTH


The implications are staggering

True interconnectedness: Nothing exists in isolation


Even in modern social media culture, can you separate YOU from everything else?

True interconnectedness



The problem is that we feel isolated

True interconnectedness: This is about YOU



It is not only about the physical planet Earth, it is about OUR bodies, minds, spirits, and relationships that are being trashed and polluted


We are being told that we are isolated, not good enough, not important to the big picture


But it’s not true


We have to start telling – and believing - a different story


To make progress we must bustdown some of the walls of separation!

True interconnectedness: Friday open discussion


What are the impediments to feeling connected?


In our societies?


In our classrooms?


In our psyches?


Others?


Choose a subject to write about or find an article to discuss
Submit an short paragraph of your conclusions to Brightspace for participation